In U.S. Pat. No. 5,964,064 “Theater with multiple screen three dimensional film projection system” a theater is disclosed including an audience seating area, a stage and at least three projection screens. Right and left projection screens are positioned at an angle to the center projection screen. Multiple film projectors simultaneously project a three dimensional film onto the three projection screens. Three dimensional film elements appear to move seamlessly from one projection screen to the next. In a live action show, actors, stage sets and show action equipment appear to interact with the three dimensional film. The filmed set blends with the stage sets to give dimension and a feeling of depth to the viewing audience. The audience cannot easily distinguish between the real elements and filmed elements thereby intensifying the theater experience.
In the proposed settings, the light reflected by e.g. the left screen will reach not only the audience but also the center screen and the right screen. The same holds mutatis mutandis for the light reflected by the center screen and the right screen. This usually causes visual artefacts that will impact the viewer experience negatively.
A similar problem exists for images projected on dome shaped screen where images can be projected by two or more projectors. In U.S. Pat. No. 6,909,543 “Foveated Display System”, an improved theater geometry is disclosed which is capable of providing improved image resolution and improved image contrast over prior systems. This is achieved with a unique projection geometry and image re-mapping technique. The projected image is provided with a continuously variable image resolution and brightness over the surface of a preferably dome-shaped screen which is to receive the image, concentrating the resolution and the brightness of the image within the central field-of-view of viewers that are unidirectionally seated in the theater, and sacrificing resolution and brightness toward the outside edges of the viewers' field-of-view. The result is a more efficient use of available projector resolution and brightness, an increase in the number of quality seats available in the theater, and an enhanced image contrast due to reductions in the light which is scattering from image elements on the sides and to the rear of the screen.
If applied to a theater as described in U.S. Pat. No. 5,964,064, contrast and resolution would be highest on the central screen and would decrease on the lateral screens. The attention of the spectators being drawn from one screen to another as three-dimensional film elements appear to move seamlessly from one projection screen to the next, the central field of view of viewers can move rapidly from one screen to another. Without adaptation, the method proposed in U.S. Pat. No. 6,909,543 will lead to situations where the spectators will experience variation in brightness not linked to the content of the images being projected, but to the screen on which they are projected.
U.S. Pat. No. 8,149,508 “System for providing an enhanced immersive display environment” discloses an immersive dome including a number of novel features designed to enhance the performance of the immersive dome over other immersive dome environments. Projectors are mounted in a multi-tier tower, out of sight beneath a viewing platform positioned to provide optimal wrap-around viewing. The projection surface consists of open-cell foam that allows passage of behind-surface sound into the dome while allowing unwanted ambient noise within the dome to escape. A visually-reflective coating, in conjunction with the open cell structure, provides a textured surface that acts as a micro-baffle and suppresses cross-reflection of projected imagery. The surface of the screens is structured with a plurality of cavities defining vertical walls that extend into the screen from the projection surface; wherein said plurality of cavities terminate before extending through the screen, and wherein the plurality of cavities form micro-baffles; and wherein light at near normal incidence is reflected and wherein light at oblique angles of incidence is trapped and absorbed by said cavities for suppressing visible cross-reflectance. Projection having to be done perpendicularly to a screen, the proposed solution cannot be transposed to theater settings where one or more projectors cannot be placed so as to project perpendicularly to a screen without loss of luminosity and creating visual artefacts.
As was the case with the other solutions described, the solution described in U.S. Pat. No. 8,149,508 will not be effective when the spectators are spread over a large area and away from a central position or “sweet spot”.
Similar problems exists with the solution proposed in U.S. Pat. No. 7,548,369 “Projection-receiving surface comprising a single sheet formed into a plurality of catenoid-like mirrorlettes”, where the sweet spot is along a perpendicular to each screen element. The field of view can be tuned but is always centered on the normal to the screen elements. Therefore, the problem is not solved: increasing the field of view is possible by decreasing the cut-off rate of the screens but then the contrast of the image projected on one screen element is reduced by the light reflected on other screen elements. Furthermore, the optical axis of the projector has to be aligned with the normal to the screen which imposes restrictions to the position that the projectors can take relatively to the screen on which they project.
In the system disclosed in U.S. Pat. No. 7,221,506, entitled “Method and system for projecting audio and video in an outdoor theater”, images are projected onto two adjacent screens whereby one screen is movable with respect to the second screen. A projection system disposed generally in front of the two screens is capable of displaying images on each screen independently when the two screens are in an “open” position or on both screens together when the two screens are configured in a “closed” position. In a first “open” configuration, the images viewable on one screen are not viewable to the viewers of images on an adjacent screen and, in a second “closed” configuration, images are displayed on both screens together (forming a single, planar viewing surface) so as to be viewable by all members of the audience. In addition, a berm is configured between the viewing area of one screen and the viewing area of the other screen to create an audio and visual barrier between the two screens.
In the arrangement disclosed in JP 2008-175960, mirrors are installed between the projection devices and screens so that distances from the projection devices to the screens may be the same as distances from the observer seat to the screens, with a view to providing projection video with which a feeling of presence is obtained without a sense of incongruity as seen from an observer seat.